1. Field of the Invention
The present invention relates to a USB multi-function connecting device and in particular to a connecting device for connecting computer peripheral devices for data transfer with the peripheral devices having user-defined and serious form connection.
2. Related Arts
Computers are currently used for data processing and managing and control. However, in the structure of the computer, besides the central processing unit that is used to perform calculation and instruction execution, there are a number of secondary devices and substructures which are mainly peripheral devices for data/signal input/output, such as keyboard, joy stick, modem, printer, scanner, card reader, bar code reader and so on. Each of peripheral devices has to communicate with the computer by means of an interface card which serves as the control and data transfer means of the peripheral device. The most well known interfaces for computer peripheral devices are RS-232 and RS-422 which are standard computer interfaces. Quite apparent, the interface connection is of vital importance for the operation of the peripheral devices.
Conventionally, the computers or processor based controllers used in industrial control operation usually adapt the so called multi-port card mode which has to be coupled to an ISA bus in order to function properly. Thus, this kind of ISA bus based multi-port card has several disadvantages, such as:
(1) The computer or controller has to be taken apart in order to install the multiport card.
(2) the number of the multi-port cards that may be used in a computer or a controller have to be the power of 2, such as 2, 4, 8 and 16 so that it imposes a constraint on the use of the interface card and the non-used cards would become a waste and consume additional power.
(3) the computer or controller has to be shut down or turned off in replacing or repairing a malfunctioning multi-port card which causes unnecessary trouble for those systems that are difficult or not allowed to shut down.
(4) it has a high manufacturing cost, is hard to maintain and has a poor efficiency in industrial utilization.
(5) the interface card of each of the multi-port cards may only be a single function interface, such as RS-232 or RS-422, and the peripheral device connected thereto must be fixed and cannot be changed freely, such as a joy stick or other fixed peripheral device; this limits the use and connection of the peripheral device to the computer; further it is very troublesome and requires more cost if it is to connect an RS-422 to an RS-232 interface and vice versa.
Further, currently, connections that made based on the USB mode are done by means of the bus topology, such as the connection architecture shown in FIG. 6, wherein each HUB can only be connected in series to other HUBs in the upstream direction and the downstream direction. Each HUB has a number of options of function. Although it is free of limitation in the selection of the functions, it has a disadvantage that when one of the HUB breaks down or malfunctions, then the HUBs that are located at lower (downstream) levels have to be shut off for the replacement or change of the malfunctioning upper level HUB. This significantly influences the operation and efficiency of the system. Further, each USB device is not matured function of each HUB is fixed, meaning it cannot be modified or defined in accordance with the peripheral device associated therewith. This makes the varieties and installation of the HUBs very complicated and it is difficult to design the overall system based on the use of the HUBs. Thus, in this case, a considerable inconvenience and difficulty would be had in mounting and using peripheral devices or peripheral monitoring devices with the HUB system.
In addition, in Taiwan patent publication No. 292369, a typical USB connection module is disclosed, which is, quite obviously, similar to the HUB system shown in FIG. 6, having a few fixed function modes to be user selected, namely it only has a choice between serving a joy stick or serving a mouse. Besides the same problem in peripheral device connection as that between HUBs, an even worse problem is that the function mode cannot be freely modified or changed in accordance with the peripheral device to be connected thereto and this makes the same constraint as that of the HUB system shown in FIG. 6 so that the system connection and the operation efficiency are similarly remarkably affected.